For most men who post on this site, 15 grams/day is practically dry.
I've just passed my 2nd anniversary from DaVinci. After the first year, I started weighing every day hoping I could see a downward trend. Despite using exotic curve smoothing techniques, the daily weighing was all over the chart from a low of 11 grams to a high of 500 grams/ day if I exercised a lot and then had a large, spicy meal.
As you can see from my signature, I did kegels, bio-feedback and had two collagen infusions. After all was said and done, I was still averaging 180 grams/day.
I had sling surgery on Sept 5.2008 and am now dry.
As to your question, I have an old chart I downloaded from a site which no longer exists showing weeks since surgery vs pad weight.
(Done by Anna Smithers in 2007. You can find more current work by Googling her)
It shows that at 35 weeks, 98% of men were < 50 grams, 92% < 10 grams and 84% < 1 gram.
This is in line with what my Uro said, that 95% of men are dry after one year (My personal opinion is that this is overstated, but that's just me).
You don't say what you've done to try to improve. Are you doing Kegels? Are you sure you're doing them correctly? Bio-feedback can help that. Collagen infusions will help for a sort time, but is rarely a permanent fix.
I'm very encougaged with the AdVance Male Sling procedure I had 5 weeks ago.(See my previous posts). For men under 200 grams/day it's a good solution.